Prep, prime and paint in two or three thin coats so a light colour fully hides a dark one underneath.
PD-01Clear and protect the roomMove furniture to the centre of the room or out completely, and cover everything with dust sheets. Take down curtains. If you want to remove switch and socket plates, first switch that circuit off at the consumer unit and prove it dead with a socket tester or voltage tester — the switch on the wall doesn't make the terminals safe — and keep it off until the plates are back on. Open a window for ventilation.
PD-02Fill holes and sand smoothFill any cracks, nail holes or dents with a ready-mixed filler and a filling knife. Leave it to dry fully, then sand flush with fine sandpaper. Wipe away dust with a damp cloth before you go any further.
PD-03Wash the walls downClean the walls with sugar soap on a sponge to remove grease, dust and any nicotine staining. This helps the new paint stick properly and stops flat patches showing through the finish. Rinse with clean water and let the walls dry fully.
PD-04Mask up the edgesRun masking tape along the skirting, ceiling line, window frames and any fixed fittings you're not painting. Press the tape down firmly so paint can't creep underneath. This step takes time but saves you having to touch up sharp lines afterwards.
PD-05Apply a stain-blocking primer coatDark colours, especially reds, blacks and dark blues, can bleed through new paint for months without a proper base coat. Roll on a stain-blocking or high-opacity primer over the whole wall, cutting in at the edges with a brush first. Let it dry fully before moving on — check the tin for the drying time.
PD-06Apply the first topcoatCut in around the edges with a brush, then roll the main areas in overlapping W-shapes to keep the coverage even. Work in good light so you can spot any thin patches as you go. Leave to dry fully before the next coat.
PD-07Apply a second coat, and a third if neededOnce the first coat is dry, apply a second full coat the same way. Check the walls in daylight from a few angles — dark colours often still show a faint shadow through two coats. If you can see it, apply a third coat once the second has dried.
PD-08Remove tape and tidy upPeel off the masking tape slowly while the final coat is still slightly tacky, pulling it back on itself at a shallow angle to keep the edge crisp. Wash brushes and rollers in warm water, or leave synthetic ones wrapped in cling film if you're painting again the next day. Reseal paint tins and let the room air out before putting furniture back.